On Facebook, Michael Licona expressed ambivalence about public policy regarding homosexual marriage. He suggested that since the US is not a theocracy, we shouldn't ban homosexual marriage. In addition, he compared homosexual marriage to religious liberty.
Let's consider some basic problems with that argument.
i) If homosexual marriage is treated as a civil right or Constitutional right, then it becomes the duty of the Federal gov't to oppose state laws that deny or infringe a civil right.
That's not just a question of gov't "allowing" the practice, but the Federal gov't disallowing state gov't to conflict with Federal policy.
ii) Likewise, if it's elevated to the status of a civil right or Constitutional right, then it becomes a balancing act when that alleged right comes into conflict with other Constitutional rights (e.g. freedom of religion, expression, association).
Other rights, which are explicitly protected in and by the Constitution, will be abridged to make room for this new alleged right.
iii) In addition, it depends on what Licona means by "theocracy." Does he mean religious principles have no place in social policy?
One classic argument against homosexuality appeals to natural law. That's implicitly religious.
By contrast, people who subscribe to naturalistic evolution deny natural teleology. They deny proper function in nature. On that view, homosexuality is just a natural variation.
If, however, Licona thinks that religious principles are disallowed in that sense, then the law must treat all "natural" behavior alike. There is no natural right or wrong. Consider the legal and social consequences of that outlook. As one philosopher put it:
If we really took this line of reasoning seriously, we'd have to apply it to other conditions that virtually no one wants to see as perfectly normal. For example, one could argue that pedophilia is just a different way of being, and we should respect it. After all, it's caused by a brain condition, and all brain conditions are equally good. In terms of the arguments I see from the neurodiversity movement, I see no way to say the things they say while avoiding such a conclusion. There are plenty of ways to distinguish between the two cases, but I don't see how those are available given the extreme sorts of statements that I regularly see among neurodiversity advocates.But on one level, I can't blame the neurodiversity movement (and the more general relativistic outlook among other disability communities). After all, their view follows fairly easily from a particular version of secularized naturalistic thinking. Different neurological conditions stem from natural variation, and there's no other level of explanation but natural variation. There's no God who designed human beings to have certain capabilities. There are no natural purposes according to which organisms have a nature, and certain capacities are part of what a well-functioning member of their species will be able to do. There's no notion of well-functioning if your worldview doesn't allow for higher-level explanations about purposes and design, other than perhaps simply asking whether a particular organism fits into the way most members of its species are or whether it fits the patterns members of its species typically desire for themselves. There's nothing objective about what a healthy member of that species or a well-functioning member of that species would be like. There is no way we can have a notion of the way we ought to be if there's no ground for what it would be to be the way we ought to be.
iv) There's also the general problem of grounding social mores if you rule out religion. If secular reasoning can't justify objective moral norms, then public policy because an arbitrary exercise in power.